I have noticed the lament surrounding the lack of one wire support. It might make sense to take a higher level systems approach and simply offload the required functionality to a peripheral and talk to it via the serial port. In this regard, I am thinking of the PICAXE. The remarkable thing about the PICAXEs (aside from their cheapness) is their high level functionality. The newer parts are very interesting,
http://www.picaxe.co...s/picaxem2.pdf.
For a list of commands,
http://www.picaxe.com/BASIC-Commands
For 1-wire commands, see (Advanced I/O Interfacing), owin and owout on this page. Also, look at,
http://www.picaxefor...evices-Networks
At the bottom of this page there is a very nice 1-wire tutorial (WA55 1-Wire Tutorial RevA.pdf‎, you need to register to download)
The minimal parts count to get one working are a couple of resistors for the serial interface, a capacitor and the chip. The drawback is the PICAXE inverted serial so a couple of transistors or a 74HC04 is needed to make the serial port compatible with a Netduino. So my thought is to get an Arduino prototyping shield, install a PICAXE-20X2 and then use my Netduino Plus to manage the sensors connected to the PICAXE. I have used the PICAXE 08M for infrared interfacing and can say that they really make things easy.
A good source of USA parts is,
www.phanderson.com/picaxe/index.html
Baxter
What About PICAXE for 1-Wire Support
Started by baxter, Jan 13 2012 09:34 PM
6 replies to this topic
#2
neslekkim
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Posted 14 October 2012 - 05:27 PM
the picaxe is only an pic with some firmware on it, is that firmware available?, or do one need to purchase it as an picaxe chip?
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Asbjørn
#3
Geancarlo2
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Posted 14 October 2012 - 05:52 PM
IMO, Netduino should provide One-Wire support in the standard firmware instead lol
#4
neslekkim
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Posted 14 October 2012 - 05:57 PM
Yes. that's true, but sometimes it's not bad to offload various functionality, and comunicate it over spi, i2c or something, but it seems that picaxe is an deadend, closedsource solution?
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#5
baxter
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Posted 14 October 2012 - 07:10 PM
Hi neslekkim,
I commented on the Picaxe again here (post 25) relative to 1-wire,
http://forums.netdui...__20#entry37046
I think you are missing the point. My suggestion is to simply treat the Picaxe as a very smart peripheral. Why does it matter that it is a closed source solution? Look at the code in my cited post. 1-wire interfacing doesn't get any simpler than this and it also carries over to other functionality. In short, using them in this manner saves code space on the Netduino and provides something that works out of the box. The free programming editor is very easy to use and avoids the grief of setting up a development tool chain. If you browse the Picaxe forum, you can probably find code that someone written to do what you want,
http://www.picaxefor...ve-PICAXE-Forum
The code running on the shield in my post was obtained directly from the forum. Regarding the firmware, it is built into the manufactured chip by Microchip. The X2 suffix parts are the ones that get close the hardware for 1-wire, I2c ...
Baxter
#6
neslekkim
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Posted 14 October 2012 - 07:20 PM
I didn't miss the point about using it as an peripheral, that's what I mean with offloading functionality, so one could use an chip like this of onewire, i2c etc, but I was under the impression that picaxe is not an microchip product, but an pic controller with custom firmware, just like the arduino's are an avr chip with custom bootloader.
After searching the picaxe website, it's confirmed that I cannot upgrade the firmware in an "picaxe", so.. since there are other options that do similar things, I would use those, that I can control, and upgrade, than an closed package.
Even if it is an good one, but the day it doesnt behave as suspected, i have an brick.
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#7
baxter
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Posted 14 October 2012 - 07:50 PM
To each his own ... Here is another interesting solution for offloading tasks,
http://www.futurlec....M32_Stamp.shtml
This has a 512K, stm32f103re chip. I received my a few days ago and managed to install eLua on it.
http://www.eluaproje...8/en_index.html
I am still trying to understand Lua. It is a high level language, but eLua is a work in progress and
I don't know whether it has much to offer. You can put whatever firmware you want on this.
Baxter
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